Electric control system for driving an electric vehicle

ABSTRACT

An electric motor for driving a wheel of a vehicle may be arranged to be supplied with electric power, through a chopper control system using controlled rectifiers, from an electric battery group connected in parallel with an electric generator driven by a driving machine such as a prime mover. The efficiency of the driving system can be increased and the temperature rise of the electric battery can be kept low by providing an inductor which permits discharging D.C. current to flow from the electric battery and prevents charging current of high frequency from flowing to the electric battery.

1451 Mar. 12, 1974 ELECTRIC CONTROL SYSTEM FOR DRIVING AN ELECTRICVEHICLE [75] Inventor: Fukuo Shibata, Nishinomiya, Japan [73] Assignee:Kawasaki Jukogyo Kabushiki Kaisha, Hyo'go, Japan 22 Filed: Sept. 15,1972 21 App]. No.: 289,383

[30] Foreign Application Priority Data Lee 180/65 R GENERATOR PrimaryExaminerStanley H. Tollberg Attorney, Agent, or Firm-Sughrue, Rothwell,Mion, Zinn & Macpeak [5 7] ABSTRACT An electric motor for driving awheel of a vehicle may be arranged to be supplied with electric power,through a chopper control system using controlled rectifiers, from anelectric battery group connected in parallel with an electric generatordriven by a driving machine such as a prime mover. The efficiency of thedriving system can be increased and the temperature rise of the electricbattery can be kept low by providing an inductor which permitsdischarging D.C. current to flow from the electric battery and preventscharging current of high frequency from flowing to the electric battery.l

11 Claims, 5 Drawing Figures Kuriyama et a]. 180/65 I PAIENTEDIAR 1 2I974 SHEET 1 OF 2 PRIME MOVER 2 GENERATOR 9 N MOTOR PRIME MOVERGENERATOR FIG 5 MOTOR PAIENTED m 1 2 1974 sum 2 or z ELEC SOURCE PRIMEMOVER 24 CONTROLLER CONTROLLER 23 FIG. 4

ELECTRIC CONTROL SYSTEM FOR DRIVING AN ELECTRIC VEHICLE BACKGROUND OFTHE INVENTION 1. Field of the Invention This invention is related to anelectric control system for driving an electric vehicle whose wheel canbe driven by an electric motor supplied with electric power from anelectric battery group connected in parelectric vehicle is supplied withelectric power from an electric battery group. However, when an electricmotor for driving a wheel of an electric vehicle is supplied withelectric power from only an electric battery group, the distance overwhich the electric vehicle can run by one charged electric quantity ofthe battery is very short. In order to make the running distance of theelectric vehicle longer, a hybrid power source for the electric vehiclewas devised.

In some prior electric driving systems for the electric vehicle, a wheelis driven by an electric motor supplied with electric power from anelectric battery group connected in parallel with an electric generatordriven by a driving machine such as a prime mover. The following areexamples of the prime movers used: (1) gasoline engine, (2) dieselengine (3) steam engine (4) sterling engine (5) rotary engine (6) gasturbine (7) steam turbine (8) air turbine (9) nitrogen turbine.

In many cases of the prior electric driving systems for the electricvehicles, direct current motors are used for driving the wheels of thevehicles. When a direct current motor driving a wheel of an electricvehicle is supplied with electric power from a direct current sourcesuch as an electric battery group connected electrically in parallelwith an electric generator driven by a prime mover, a chopper systemusing controlled rectifiers such as thyristors, power transistors, etc.,is very useful for controlling the electric motors over a wide speedrange without sacrificing the efficiency of system in general. However,there is a technical problem in a chopper system using controlledrectifiers when an electric motor is supplied with electric power froman electric source of a parallel connection of an electric battery groupand an electric generator driven by a prime mover.

When the electric motor driving the load is controlled by a chopperwhich is connected electrically in the motor circuit, voltage rise andfall of high frequencies are produced in the electric circuit of thechopper. The peak voltage rise occurs in the chopper circuit during theinstant when the electric motor circuit is interrupted by the operationof a chopper which controls the supplied average voltage of the electricmotor. The electric battery group is charged from the electric generatordriven by the prime mover during the instant when the peak voltage riseis produced. The electric power which instantaneously charges theelectric battery'from the electric generator driven by the prime moveris discharged in the subsequent instant, to supply the electric motor.When an electric battery is unnecessarily charged from an electricsource, a charging loss is produced in the electric battery group. Whenan electric battery is discharged for supplying a load, a dischargingloss is produced in the electric battery. Therefore, if the electricbattery is charged and discharged, the charging and discharging lossesare produced in the electric battery, and then the efficiency of theelectric control system becomes low. In other words, the efficiency oftransmitting electrical power from the generator to the motor throughthe battery becomes considerably lower than the efficiency oftransmitting an electrical power directly from the generator to themotor. Further, an unnecessary temperature rise of the electric batteryoccurs when electric power is transmitted from the generator to themotor through the process of charging and discharging of the battery. 7

SUMMARY OF THE INVENTION It is the primary object of the invention toprovide an electric control system for driving an electric vehicle inwhich an electric motor driving a wheel'of the electric vehicle issupplied with electric power from an electric source of a parallelconnection of an electric battery group and an electric generator drivenby a driving machine such as a prime mover without sacrificingefficiency of operation of the system by preventing the unnecessarycharging and discharging of the battery.

Another object of this invention is to provide an electric controlsystem for driving an electric vehicle in which an electric motordriving a wheel of the electric vehicle is supplied with electric powerfrom combined electric sources of an electric battery group and anelectric generator driven by a driving machine such as a prime moverwithout producing unnecessary temperature rise in the electric batterygroup.

A further'object of this invention is to reduce consid erably the spaceof installation of an electric control system for driving an electricvehicle and the weight of the electric battery group installed in anelectric vehicle.

Other objects of this invention will in part be obvious and in partappear hereinafter.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1, FIG. 2, FIG. 3 and FIG. 5illustrate diagram matically systems of this invention.

FIG. 4 illustrates a portion of the embodiment shown in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, an electriccontrol system for driving an electric vehicle of this inventionincludes a wheel 10 by which the vehicle can be driven forward. Anelectric generator 2 which has output terminals 15 is driven by a primemover 1. An electric motor 9 which has input terminals 19 and has arotor is arranged to drive the wheel 10 of the vehicle, and an electricbattery group 7 has output terminals F, G connected electrically withthe input terminals 19 of the electric motor 9 and with the outputterminals 15 of the electric generator 2. A rectifier 6 is connected sothat only discharging current of the electric battery 7 flowstherethrough. Connected in parallel with rectifier 6 is an inductor 5which passes DC. and low frequency charging current and also passes theDC. battery discharge current, but blocks high frequency chargingcurrents.

The following machines are shown as examples of a prime mover: (l)gasoline engine'(2) diesel engine (3)- 3 steam engine (4) sterlingengine (5) rotary engine (6) gas turbine (7) steam turbine (8 airturbine (9) nitrogen turbine.

In FIG. 1, a chopper 8 comprising controlled rectifiers is connectedelectrically with the electric motor'9 which is a direct current motor.The voltage supplied on the input terminals 19 of the direct currentmotor 9 from the electric source can be controlled by controlling thechopper 8. The electric source is composed of an electric generator 2 ofwhich the output terminals '15 are connected electrically with theoutput terminals F, G of the electric battery group 7. In FIG. 1,theelectric generator is an alternating current generator 2 of which theoutputterminals are connected electrically with the output terminals F,G of the electric battery group 7 through a converter 3 composed ofrectifiers. An inductor 5 is connected electrically. in parallel withthe rectifier 6 in the electric circuit which is connected between theoutput terminals 15 of the electric generator 2 and the output terminalG of the electric battery group 7. A condenser 4 is connectedelectrically with the output tenninals 15 of the electric generator 2 sothat the condenser 4 may be supplied with electric power fromthe-electric generator 2 or from the electric motor 9. When a voltagerise of high frequency is produces in the electric circuit of thechopper 8, the inductor 5 prevents the current due to the peak voltageof high frequency from flowing into the electric battery group 7, andthe condenser 4 absorbs this current. Only DC. or low frequency chargingcurrent and D.C. discharging current can flow throughthe inductor 5. Therectifier 6 permits only the DC. discharging current of the electricbattery.7 to flow therethrough.

In FIG. 2, the electric motor for driving the wheel of the vehicle is awound rotor type induction motor 9 which has a primary winding and asecondary winding and of which the primary winding is supplied withalternating current from the alternating current generator 2. Thesecondary winding is supplied with alternating current from the directcurrent source of the electric bat tery group 7 connected in parallelwith the converter 3 of theelectric generator 2 through the chopper 8and an inverter 11 which is composed of controlled rectifiers. 1

In FIG. 3, the electric generator is composed of an electro-magneticcoupling 2 having two rotors 12,13 which are rotatable with respect toeach other and one of which is provided with an armature winding. Rotor12 of the electromagnetic coupling 2 is mechanically combined with therotor of the electric motor 9 and the other rotor 13 of theelectromagnetic coupling 2 is driven by the prime mover 1. In FIG. 3,the direct current motor 9 is provided with a voltage field winding 16(shunt or separately excited field winding) and a current field winding17 (series field winding). 20 is the commutator. The current of thedirect currentmotor 9 is supplied from terminals E, F of the electricsource.

, In FIG. 3, thewheel 10 of the vehicle is drivenby the rotor shaft ofthe direct current motor. 9 combined mechanically with the rotor 12 ofthe electromagnetic coupling 2 through a gearing 18 which may be atransmission. The wheel 10 can be controlled by both or eithercontrolling a controller 23 of the voltage field winding 16 and/or acontroller 24 of the chopper 8. These controllers 23 and 24 can becontrolled by a pedal 25. Rotor 13 of the electromagnetic coupling 2 isprovided with a field winding which can be supplied 4 I with excitingcurrent from an electric source 21 through controlled rectifiers 22 andslip-rings l4. Rotor 12 of the electromagnetic coupling 2 is providedwith an armature winding which is connected electrically I with theconverter 3 composed of rectifiers through FIG. 4 illustrates a part'ofthe embodiment of construction of the arrangement shown in FIG. 3. FIG.4 shows that one, 12, of the rotors l2 and 13 of the ,electromagneticcoupling 2, is adapted to drive the wheel 10, and the other rotor, l3,of the electromagnetic coupling 2 is adapted to be driven by prime moverl.'The one rotor l3 has a circumferential inner cylindrical part 29provided with a magnetic member 31 for forming a magnetic circuit forthe electromagnetic coupling 2 and a circumferential outer cylindricalpart 30 which is provided with a magnetic member 32 forming a magneticcircuit for the electric motor 9 andthe rotor 13. The rotor of theelectric motor comprises a common rotor which rotates in a space betweenthe stator 26 of the electric motor 9 and the other rotor 12 of theelectromagnetic coupling 2. In FIG. 4, the electric motor 9 is a directcurrent motor.. I

FIG. 4 shows also that the magnetic member 27 fonning a magnetic circuitin the inner rotor 12 of the electromagnetic coupling 2 and the magneticmember 28 forming a magnetic circuit in the stator 26 of the electricmotor 9 exist together ina section AB perpendicular to a shaft of theinner rotor l2 of the electromagnetic coupling 2. In FIG. 4, thearmature winding 33 of the elctric motor is connected electrically withthe commutators 20.

In FIG. 5, theelectric generator 2 is a direct current generator ofwhich theoutput t'erminals 15 are connected electrically with the outputterminals G, F of the electric battery group 7 through the rectifier 6connected electrically in parallel with the inductor 5.

When theelectric motor 9 driving the wheel is controlled by the chopper8, voltage-rises of high frequencies are produced in the electriccircuit E, F of the chopper. Electric energy produced by these voltagerises is absorbed in the condenser 4, and cannot pass through theinductor 5. Since the rectifier- 6 blocks the charging current of thebattery'7, the electric battery 7 is not supplied withelectric powerproduced by the voltage rises of high frequencies at the chopper 8. Onlydirectcurrent electric power or low frequency electric power can passthrough the inductor 5. Theelectric battery group 7 can be charged by adirect current elecv tric power through the inductor 5 from the electricgenerator, and can be discharged through the rectifier 6.

In FIG. 2, the inverter 11 is used as a separately excited inverter. Thewound rotor type inductor motor 9 is controlled in a speed range of slipS I.

In FIG. 3, a part of the output of the prime mover 1 I can betransmitted to the load directly or mechanically through theelectromagnetic coupling 2. the other part of theoutput of the primemover 1 can be converted into electric energy through theelectromagnetic coupling.

While the invention has been particularly shown and described withreference to the preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention.

I claim:

1. An electric control system for driving an electric vehiclecomprising:

a. wheel means for driving the vehicle;

b. electric generator means having output terminals;

c. a prime mover arranged to drive said electric generator means; Y

(1. electric motor means including input terminals and a rotor arrangedto drive said wheel;

e. an electric battery group having output terminals connected to saidinput terminals of the electric motor means and to said output terminalsof the electric generator means; and

f. inductor means connected electrically, in the closed D.C. circuitincluding said electric battery group and said electric motor means, inseries with one of said output terminals of the electric generator meansand one of said output terminals of the electric battery group forpermitting D.C. discharge current to flow from the electric batterygroup to said input terminals of the electric motor means and forpreventing high frequency charging current from flowing to the electricbattery group.

2. An electric control system for driving an electric vehicle as setforth in claim 1, further including a chopper means comprisingcontrolled rectifiers connected to the electric motor means, forcontrolling the current supplied to said motor means.

3. An electric control system for driving an electric vehicle as setforth in claim 1, further including rectifier means connectedelectrically in parallel with said inductor means for providing ad. c.discharge path for the electric battery group.

4. An electric control system for driving an electric vehicle as setforth in claim 1, further including a condenser connected electricallywith the output terminals of the electric generator means wherein thecondenser may be supplied with electric power from the electricgenerator means.

5. An electric control system for driving an electric vehicle as setforth in claim 1, wherein the electric generator means is analtemating'current generator having outputterminals connected to theoutput terminals of the electric battery group through converter meanscomprising rectifiers.

6. An electric control system for driving an electric vehicle as setforth in claim 1, wherein the electric generator means is a directcurrent generator having output terminals connected to the outputterminals of the electric battery group.

7. An electric control system for driving an electric vehicle as setforth in claim 1, wherein the electric generator means includes anelectromagnetic coupling having two rotors, rotatable with respect toeach other, wherein one of the rotors is provided with an armaturewinding, and wherein one of the rotors is mechanically combined with therotor of the electromagnetic coupling driven by said prime mover.

8. An electric control system for driving an electric vehicle as setforth in claim 1, wherein the electric generator means comprises anelectromagnetic coupling having two rotors which are rotatable withrespect to each other wherein one of the rotors is provided with anarmature winding and wherein one of the rotors is adapted to drive thewheel, and the other of the rotors is adapted to be driven by said primemover, the one rotor having a circumferential inner cylindrical partineluding a magnetic member forming a magnetic circuit for theelectromagnetic coupling and a circumferential outer cylindrical partincluding a magnetic member forming a magnetic circuit for the electricmotor means and the one rotor and the rotor of the electric motor meanscomprising a common rotor which rotates in a space between the stator ofthe electric motor means and the other rotor of the electromagneticcoupling.

9. An electric control system for driving an electric vehicle as setforth in claim 8, wherein the electric motor means is a direct currentmotor.

10. An electric control system for driving an electric vehicle as setforth in claim 1, wherein the electric motor means is a direct currentmotor.

11. An electric control system for driving an electric vehicle as setforth in claim 1, wherein the electric motor means is a wound rotor typeinduction motor wherein the input terminals of the induction motor aresupplied with electric powerfrom the electric battery group.

1. An electric control system for driving an electric vehiclecomprising: a. wheel means for driving the vehicle; b. electricgenerator means having output terminals; c. a prime mover arranged todrive said electric generator means; d. electric motor means includinginput terminals and a rotor arranged to drive said wheel; e. an electricbattery group having output terminals connected to said input terminalsof the electric motor means and to said output terminals of the electricgenerator means; and f. inductor means connected electrically, in theclosed D.C. circuit including said electric battery group and saidelectric motor means, in series with one of said output terminals of theelectric generator means and one of said output terminals of theelectric battery group for permitting D.C. discharge current to flowfrom the electric battery groUp to said input terminals of the electricmotor means and for preventing high frequency charging current fromflowing to the electric battery group.
 2. An electric control system fordriving an electric vehicle as set forth in claim 1, further including achopper means comprising controlled rectifiers connected to the electricmotor means, for controlling the current supplied to said motor means.3. An electric control system for driving an electric vehicle as setforth in claim 1, further including rectifier means connectedelectrically in parallel with said inductor means for providing a d. c.discharge path for the electric battery group.
 4. An electric controlsystem for driving an electric vehicle as set forth in claim 1, furtherincluding a condenser connected electrically with the output terminalsof the electric generator means wherein the condenser may be suppliedwith electric power from the electric generator means.
 5. An electriccontrol system for driving an electric vehicle as set forth in claim 1,wherein the electric generator means is an alternating current generatorhaving output terminals connected to the output terminals of theelectric battery group through converter means comprising rectifiers. 6.An electric control system for driving an electric vehicle as set forthin claim 1, wherein the electric generator means is a direct currentgenerator having output terminals connected to the output terminals ofthe electric battery group.
 7. An electric control system for driving anelectric vehicle as set forth in claim 1, wherein the electric generatormeans includes an electromagnetic coupling having two rotors, rotatablewith respect to each other, wherein one of the rotors is provided withan armature winding, and wherein one of the rotors is mechanicallycombined with the rotor of the electromagnetic coupling driven by saidprime mover.
 8. An electric control system for driving an electricvehicle as set forth in claim 1, wherein the electric generator meanscomprises an electromagnetic coupling having two rotors which arerotatable with respect to each other wherein one of the rotors isprovided with an armature winding and wherein one of the rotors isadapted to drive the wheel, and the other of the rotors is adapted to bedriven by said prime mover, the one rotor having a circumferential innercylindrical part including a magnetic member forming a magnetic circuitfor the electromagnetic coupling and a circumferential outer cylindricalpart including a magnetic member forming a magnetic circuit for theelectric motor means and the one rotor and the rotor of the electricmotor means comprising a common rotor which rotates in a space betweenthe stator of the electric motor means and the other rotor of theelectromagnetic coupling.
 9. An electric control system for driving anelectric vehicle as set forth in claim 8, wherein the electric motormeans is a direct current motor.
 10. An electric control system fordriving an electric vehicle as set forth in claim 1, wherein theelectric motor means is a direct current motor.
 11. An electric controlsystem for driving an electric vehicle as set forth in claim 1, whereinthe electric motor means is a wound rotor type induction motor whereinthe input terminals of the induction motor are supplied with electricpower from the electric battery group.